Quality of service rule management in 5G

ABSTRACT

A method of managing default QoS rules for PDU session is proposed. A PDU session defines the association between the UE and the data network that provides a PDU connectivity service. Each PDU session is identified by a PDU session ID, and may include multiple QoS flows and QoS rules. There can be more than one QoS rule associated with the same QoS flow. A default QoS rule is required to be sent to the UE for every PDU session establishment and it is associated with a QoS flow. Within a PDU session, there should be one and only one default QoS rule. In one novel aspect, UE behavior and error handling for proper QoS rule management is defined for PDU session establishment and modification procedures to enforce the one and only one default QoS rule policy.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 from U.S.Provisional Application No. 62/655,137, entitled “5GSM Enhancement onInterworking”, filed on Apr. 9, 2018, the subject matter of which isincorporated herein by reference.

TECHNICAL FIELD

The disclosed embodiments relate generally to wireless communication,and, more particularly, to method of managing Quality of Service (QoS)rules in 5G new radio (NR) systems.

BACKGROUND

The wireless communications network has grown exponentially over theyears. A Long-Term Evolution (LTE) system offers high peak data rates,low latency, improved system capacity, and low operating cost resultingfrom simplified network architecture. LTE systems, also known as the 4Gsystem, also provide seamless integration to older wireless network,such as GSM, CDMA and Universal Mobile Telecommunication System (UMTS).In LTE systems, an evolved universal terrestrial radio access network(E-UTRAN) includes a plurality of evolved Node-Bs (eNodeBs or eNBs)communicating with a plurality of mobile stations, referred to as userequipments (UEs). The 3^(rd) generation partner project (3GPP) networknormally includes a hybrid of 2G/3G/4G systems. The Next GenerationMobile Network (NGMN) board, has decided to focus the future NGMNactivities on defining the end-to-end requirements for 5G new radio (NR)systems.

Quality of Service (QoS) indicates the performance from the perspectiveof network users. In LTE Evolved Packet System (EPS), QoS is managedbased on EPS bearer in the Evolved Packet Core (EPC) and the RadioAccess Network (RAN). In 5G network, QoS flow is the finest granularityfor QoS management to enable more flexible QoS control. The concept ofQoS flow is like EPS bearer. All types of traffic mapped to the same LTEEPS bearer or to the same 5G QoS flow receive the same level of packetforwarding treatment (e.g., scheduling policy, queue management policy,rate shaping policy, RLC configuration etc.) Providing different QoSforwarding treatment requires separate 5G QoS flow. Each QoS flow mayinclude multiple QoS rules consisting of QoS profile, packet filters,and precedence order. QoS profile includes QoS parameters and QoSmarking. Packet filter is used for binding a QoS flow to a specific QoSmarking. Precedence order represents the priority to adapt a QoS rule toa QoS flow. UE performs the classification and marking of uplink (UL)User Plane traffic, i.e., the association of UL traffic to QoS flowsbased on QoS rules.

In 5G, PDU session establishment is a parallel procedure of PDNconnection procedure in 4G. A PDU session defines the associationbetween the UE and the data network that provides a PDU connectivityservice. Each PDU session is identified by a PDU session ID, and mayinclude multiple QoS flows and QoS rules. Each QoS flow is identified bya QoS flow ID (QFI) which is unique within a PDU session. Each QoS ruleis identified by a QoS rule ID (QRI). There can be more than one QoSrule associated with the same QoS flow. A default QoS rule is requiredto be sent to the UE for every PDU session establishment and it isassociated with a QoS flow.

Within a PDU session, there should be one and only one default QoS rule.However, the network may send multiple QoS rules to UE as the defaultQoS rule, the network may want to delete the default QoS rule, and thenetwork may want to modify the default QoS rule. It is thus desirable todefine the UE behavior and error handling for proper QoS rulemanagement.

SUMMARY

A method of managing default QoS rules for PDU session is proposed. APDU session defines the association between the UE and the data networkthat provides a PDU connectivity service. Each PDU session is identifiedby a PDU session ID, and may include multiple QoS flows and QoS rules.Each QoS flow is identified by a QoS flow ID (QFI) which is uniquewithin a PDU session. Each QoS rule is identified by a QoS rule ID(QRI). There can be more than one QoS rule associated with the same QoSflow. A default QoS rule is required to be sent to the UE for every PDUsession establishment and it is associated with a QoS flow. Within a PDUsession, there should be one and only one default QoS rule. UE behaviorand error handling for proper QoS rule management is defined for PDUsession establishment and modification procedures to enforce the one andonly one default QoS rule policy.

In one embodiment, a UE transmits a protocol data unit (PDU) sessionestablishment request in a mobile communication network. The UE receivesa PDU session establishment accept from the network. The PDU sessionestablishment accept indicates to the UE to establish the PDU sessionand to create one or more QoS flows with one or more QoS rules. The UEreleases the PDU session when the UE determines that more than one QoSrules are set by the network to be a default QoS rule for the PDUsession.

In another embodiment, a UE establishes a protocol data unit (PDU)session in a mobile communication network. The PDU session is associatedwith a default Quality of Service (QoS) rule. The UE receives a PDUsession modification command from the network. The PDU sessionmodification command comprises commands for modifying the default QoSrule of the PDU session. The UE determines whether the PDU sessionmodification command causes a conflict for a default QoS rule policy.The UE rejects the PDU session modification command or releasing the PDUsession upon determining the conflict for the default QoS rule policy.In one example, the PDU session modification command is for the UE toadd another QoS rule as the default QoS rule. The UE rejects the PDUsession modification command by sending a PDU session modificationcommand reject message with an error code. In another example, the PDUsession modification command is for the UE to delete the default QoSrule, to delete all packet filters within the default QoS rule, or tochange the DQR setting. The UE release the PDU session by sending a PDUsession release request.

Other embodiments and advantages are described in the detaileddescription below. This summary does not purport to define theinvention. The invention is defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, where like numerals indicate like components,illustrate embodiments of the invention.

FIG. 1 illustrates an exemplary EPS/5GS network supporting Quality ofService (QoS) rule management in accordance with one novel aspect.

FIG. 2 illustrates simplified block diagrams of a user equipment (UE) inaccordance with embodiments of the current invention.

FIG. 3 illustrates a first embodiment of QoS rule management for PDUsession establishment procedure in accordance with one novel aspect.

FIG. 4 illustrates a second embodiment of QoS rule management for PDUsession establishment procedure in accordance with one novel aspect.

FIG. 5 illustrates a first embodiment of QoS rule management for PDUsession modification procedure for adding default QoS rule in accordancewith one novel aspect.

FIG. 6 illustrates a second embodiment of QoS rule management for PDUsession modification procedure for adding default QoS rule in accordancewith one novel aspect.

FIG. 7 illustrates a first embodiment of QoS rule management for PDUsession modification procedure for deleting default QoS rule inaccordance with one novel aspect.

FIG. 8 illustrates a second embodiment of QoS rule management for PDUsession modification procedure for deleting default QoS rule inaccordance with one novel aspect.

FIG. 9 is a flow chart of a method of QoS rule management for PDUsession establishment in accordance with one novel aspect.

FIG. 10 is a flow chart of a method of QoS rule management for PDUsession modification in accordance with one novel aspect.

DETAILED DESCRIPTION

Reference will now be made in detail to some embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings.

FIG. 1 illustrates an exemplary 4G LTE or 5G new radio (NR) 100 networksupporting Quality of Service (QoS) rule management in accordance withone novel aspect. LTE/NR network 100 comprises application server 111that provides various services by communicating with a plurality of userequipments (UEs) including UE 114. In the example of FIG. 1, applicationserver 111 and a packet data network gateway (PDN GW or P-GW) 113 belongto part of a core network CN 110. UE 114 and its serving base station BS115 belong to part of a radio access network RAN 120. RAN 120 providesradio access for UE 114 via a radio access technology (RAT). Applicationserver 111 communicates with UE 114 through PDN GW 113, serving GW 116,and BS 115. A mobility management entity (MME) or an access and mobilitymanagement function (AMF) 117 communicates with BS 115, serving GW 116and PDN GW 113 for access and mobility management of wireless accessdevices in LTE/NR network 100. UE 114 may be equipped with a radiofrequency (RF) transceiver or multiple RF transceivers for differentapplication services via different RATs/CNs. UE 114 may be a smartphone, a wearable device, an Internet of Things (IoT) device, and atablet, etc.

EPS and 5GS networks are packet-switched (PS) Internet Protocol (IP)networks. This means that the networks deliver all data traffic in IPpackets, and provide users with Always-On IP Connectivity. When UE joinsan EPS/5GS network, a Packet Data Network (PDN) address (i.e., the onethat can be used on the PDN) is assigned to the UE for its connection tothe PDN. EPS calls the UE's “IP access connection” an evolved packetsystem (EPS) bearer, which is a connection between the UE and the P-GW.The P-GW is the default gateway for the UE's IP access. EPS has defineda Default EPS Bearer to provide the IP Connectivity that is Always-On.

In 5G, PDU session establishment is a parallel procedure of PDNconnection procedure in 4G. A PDU session defines the associationbetween the UE and the data network that provides a PDU connectivityservice. Each PDU session is identified by a PDU session ID, and mayinclude multiple QoS flows and QoS rules. Each QoS flow is identified bya QoS flow ID (QFI) which is unique within a PDU session. Each QoS ruleis identified by a QoS rule ID (QRI). There can be more than one QoSrule associated with the same QoS flow. A default QoS rule is requiredto be sent to the UE for every PDU session establishment and it isassociated with a QoS flow.

Within a PDU session, there should be one and only one default QoS rule.However, the network may send multiple QoS rules to UE as the defaultQoS rule, the network may want to delete the default QoS rule, and thenetwork may want to modify the default QoS rule. In accordance with onenovel aspect, UE behavior and error handling for proper QoS rulemanagement is defined for PDU session establishment procedure and forPDU session modification procedure. In the example of FIG. 1, UE 114performs PDU session establishment procedure or PDU session modificationprocedure with the network over non-access stratum (NAS) layer signaling130. During the PDU session establishment or modification, UE 114performs QoS rule management as depicted by 140. In a first example, UE114 rejects a PDU session modification command if a new QoS rule is tobe added as a default QoS rule. In a second example, UE 114 releases anewly established PDU session if more than one QoS rules are to be setas a default QoS rule for the PDU session. In a third example, UE 114releases an existing PDU session if a default QoS rule of the PDUsession is to be deleted by a PDU session modification command.

FIG. 2 illustrates simplified block diagrams of wireless devices, e.g.,a UE 201 and network entity 211 in accordance with embodiments of thecurrent invention. Network entity 211 may be a base station combinedwith an MME or AMF. Network entity 211 has an antenna 215, whichtransmits and receives radio signals. A radio frequency RF transceivermodule 214, coupled with the antenna, receives RF signals from antenna215, converts them to baseband signals and sends them to processor 213.RF transceiver 214 also converts received baseband signals fromprocessor 213, converts them to RF signals, and sends out to antenna215. Processor 213 processes the received baseband signals and invokesdifferent functional modules to perform features in base station 211.Memory 212 stores program instructions and data 220 to control theoperations of base station 211. In the example of FIG. 2, network entity211 also includes a set of control functional modules and circuit 290.PDU session handling circuit 231 handles PDU session establishment andmodification procedures. QoS flow and rule management circuit 232creates, modifies, and deletes QoS flows and QoS rules for UE.Configuration and control circuit 233 provides different parameters toconfigure and control UE.

Similarly, UE 201 has memory 202, a processor 203, and radio frequency(RF) transceiver module 204. RF transceiver 204 is coupled with antenna205, receives RF signals from antenna 205, converts them to basebandsignals, and sends them to processor 203. RF transceiver 204 alsoconverts received baseband signals from processor 203, converts them toRF signals, and sends out to antenna 205. Processor 203 processes thereceived baseband signals and invokes different functional modules andcircuits to perform features in UE 201. Memory 202 stores data andprogram instructions 210 to be executed by the processor to control theoperations of UE 201. Suitable processors include, by way of example, aspecial purpose processor, a digital signal processor (DSP), a pluralityof micro-processors, one or more micro-processor associated with a DSPcore, a controller, a microcontroller, application specific integratedcircuits (ASICs), file programmable gate array (FPGA) circuits, andother type of integrated circuits (ICs), and/or state machines. Aprocessor in associated with software may be used to implement andconfigure features of UE 201.

UE 201 also comprises a set of functional modules and control circuitsto carry out functional tasks of UE 201. Protocol stacks 260 compriseNon-Access-Stratum (NAS) layer to communicate with an MME or an AMFentity connecting to the core network, Radio Resource Control (RRC)layer for high layer configuration and control, Packet Data ConvergenceProtocol/Radio Link Control (PDCP/RLC) layer, Media Access Control (MAC)layer, and Physical (PHY) layer. System modules and circuits 270 may beimplemented and configured by software, firmware, hardware, and/orcombination thereof. The function modules and circuits, when executed bythe processors via program instructions contained in the memory,interwork with each other to allow UE 201 to perform embodiments andfunctional tasks and features in the network. In one example, systemmodules and circuits 270 comprise PDU session handling circuit 221 thatperforms PDU session establishment and modification procedures with thenetwork, a QoS rule management circuit 222 that determines any conflictof the default QoS rules and handles QoS rule management, a config andcontrol circuit 223 that handles configuration and control parameters.

FIG. 3 illustrates a first embodiment of QoS rule management for PDUsession establishment procedure in accordance with one novel aspect. Instep 311, UE 301 transmits a PDN session establishment request to datanetwork 302. A PDU session is defined as an association between the UEand the data network that provides a PDU connectivity service. In step321, UE 301 receives a PDN session establishment accept from thenetwork. The accept message comprises instructions for UE 301 to createone or more QoS flows and to create one or more QoS rules for the PDNsession. In 5G networks, all types of traffic mapped to the same 5G QoSflow receive the same level of packet forwarding treatment (e.g.,scheduling policy, queue management policy, rate shaping policy, RLCconfiguration etc.) Providing different QoS forwarding treatmentrequires separate 5G QoS flow. Each QoS flow may include multiple QoSrules consisting of QoS profile, packet filters, and precedence order.UE performs the classification and marking of uplink (UL) User Planetraffic, i.e., the association of UL traffic to QoS flows based on QoSrules.

Each PDU session is identified by a PDU session ID, and may includemultiple QoS flows and QoS rules. Each QoS flow is identified by a QoSflow ID (QFI) which is unique within a PDU session. Each QoS rule isidentified by a QoS rule ID (QRI). There can be more than one QoS ruleassociated with the same QoS flow. A default QoS rule is required to besent to the UE for every PDU session establishment and it is associatedwith a QoS flow. When establishing the PDU session and creating thedifferent QoS flows and QoS rules, each QoS rule has a default QoS rule(DQR) indication indicating whether “this QoS rule is the default QoSrule”. Within a PDU session, there should be one and only one defaultQoS rule.

However, in step 321, UE 301 may receive multiple QoS rules with DQRindication set to “the QoS rule is the default QoS rule” for the PDUsession, which creates a conflict on the default QoS rule policy thereshould be one and only one default QoS rule for each PDU session. Instep 331, UE 301 evaluates the PDU session establishment accept messageand determines whether the network has indicated to the UE to createmultiple default QoS rules. If there is no conflict, then theestablished PDU session is good. Otherwise, if there is conflict fordefault QoS rule policy and multiple default QoS rules are to be createdfor the PDU session, then in step 341, UE 301 needs to decide what to dowith the established PDU session. For example, UE 301 may establish andthen release the PDU session, or ignore the PDU session establishmentand locally release the PDU session, or send a 5GSM message to thenetwork with a proper cause, e.g., PDU #N DRQ mismatch, or PDU #N DQRerror.

FIG. 4 illustrates a second embodiment of QoS rule management for PDUsession establishment procedure in accordance with one novel aspect. Forthe PDU session establishment procedure, steps 411-431 of FIG. 4 aresimilar to steps 311-331 of FIG. 3. In step 431, UE 401 determines thatdata network 402 has indicated to the UE to create multiple default QoSrules for the PDU session, which creates a conflict for the default QoSrule policy. In the embodiment of FIG. 4, UE 401 releases theestablished PDU session explicitly to resolve such conflict. In step441, UE 401 sends a PDU session release request to the network. In step451, UE 401 receives a PDU session release command from the network. Instep 461, UE releases the PDU session and confirms the release bysending a PDU session release complete to the network. Note that the PDUsession can be released implicitly, e.g., released locally within theUE. Optionally the UE may initiate a registration update procedure(e.g., by sending a registration request message) to the network for PDUsession status synchronization.

FIG. 5 illustrates a first embodiment of QoS rule management for PDUsession modification procedure for adding default QoS rule in accordancewith one novel aspect. In step 510, UE 501 sends a PDU sessionmodification request to data network 502. The PDU session modificationrequest comprises UE proposals for creating, modifying, or deleting oneor more QoS flows and/or one or more QoS rules. In step 511, network 502determines QoS parameters based on the UE proposal and based on networkpolicy and status. In step 521, network 502 sends a PDU sessionmodification command to UE 501. In the embodiment of FIG. 5, the PDUsession modification command comprises one or more new QoS rules withDQR indication set to “the QoS rule is the default QoS rule”. In anotherembodiment of FIG. 5, the PDU session modification command comprisesmodifying the DQR indication of an existing QoS rule from “the QoS ruleis not the default QoS rule” to “the QoS rule is the default QoS rule”.In step 531, upon receive the PDU session modification command, UE 501evaluates the command and checks whether such command causes anyconflict of the default QoS rule policy. When UE determines the commandcarries a new QoS rule with the DQR indication set to “the QoS rule isthe default QoS rule” or modifying the DQR indication of an existing QoSrule from “the QoS rule is not the default QoS rule” to “the QoS rule isthe default QoS rule”, UE knows that the command will create more thanone default QoS rules and thus causes conflict. In step 541, UE 501 senda PDU session modification command reject back to the network, with aproper cause, e.g., semantic error in the QoS operation, DQR mismatch orDQR error to resolve the DQR conflict. In another embodiment of step541, UE 501 send a PDU session release request to the network with aproper cause, e.g., semantic error in the QoS operation.

FIG. 6 illustrates a second embodiment of QoS rule management for PDUsession modification procedure for adding default QoS rule in accordancewith one novel aspect. FIG. 6 is similar to FIG. 5. In the embodiment ofFIG. 6, however, the PDU session modification procedure is initiated bythe network, not by the UE. In step 611, network 602 determines QoSparameters based on network policy and status. In step 621, network 602sends a PDU session modification command to UE 601. In the embodiment ofFIG. 6, the PDU session modification command comprises one or more newQoS rules with DQR indication set to “the QoS rule is the default QoSrule”. In another embodiment of FIG. 6, the PDU session modificationcommand comprises modifying the DQR indication of an existing QoS rulefrom “the QoS rule is not the default QoS rule” to “the QoS rule is thedefault QoS rule”. In step 631, upon receive the PDU sessionmodification command, UE 601 evaluates the command and checks whethersuch command causes any conflict of the default QoS rule policy. When UEdetermines the command carries a new QoS rule with the DQR indicationset to “the QoS rule is the default QoS rule” or modifying the DQRindication of an existing QoS rule from “the QoS rule is not the defaultQoS rule” to “the QoS rule is the default QoS rule”, UE knows that thecommand will create more than one default QoS rules and thus causesconflict. In step 641, UE 601 send a PDU session modification commandreject back to the network, with a proper cause, e.g., semantic error inthe QoS operation, DQR mismatch or DQR error to resolve the DQRconflict. In another embodiment of step 641, UE 501 send a PDU sessionrelease request to the network with a proper cause, e.g., semantic errorin the QoS operation.

FIG. 7 illustrates a first embodiment of QoS rule management for PDUsession modification procedure for deleting the default QoS rule inaccordance with one novel aspect. In step 710, UE 701 sends a PDUsession modification request to data network 702. The PDU sessionmodification request comprises UE proposals for creating, modifying, ordeleting one or more QoS flows and/or one or more QoS rules. In step711, network 702 determines QoS parameters based on the UE proposal andbased on network policy and status. In step 721, network 702 sends a PDUsession modification command to UE 701. In the embodiment of FIG. 7, thePDU session modification command comprises a QoS rule operation todelete the default QoS rule, to delete all packet filters within thedefault QoS rule, or to modify the default QoS rule to change the DQRsetting (i.e., set the rule as not a default QoS rule). In step 731,upon receive the PDU session modification command, UE 701 evaluates thecommand and checks whether such command causes any conflict of thedefault QoS rule policy. When UE determines the command carries a QoSrule operation to effectively delete the existing default QoS rule, UEknows that the command causes conflict for the one and only one DRQpolicy. In step 741, UE 701 send a PDU session release request to thenetwork. In step 751, UE 701 receives a PDU session release command fromthe network. In step 761, UE 701 sends a PDU session release complete tothe network. In another embodiment of step 741, UE 701 send a PDUsession modification command reject back to the network, with a propercause, e.g., semantic error in the QoS operation.

FIG. 8 illustrates a second embodiment of QoS rule management for PDUsession modification procedure for deleting default QoS rule inaccordance with one novel aspect. FIG. 8 is similar to FIG. 7. In theembodiment of FIG. 8, however, the PDU session modification procedure isinitiated by the network, not by the UE. In step 811, network 802determines QoS parameters based on network policy and status. In step821, network 802 sends a PDU session modification command to UE 801. Inthe embodiment of FIG. 8, the PDU session modification command comprisesa QoS rule operation to delete the default QoS rule, to delete allpacket filters within the default QoS rule, or to modify the default QoSrule to change the DQR setting (i.e., set the rule as not a default QoSrule). In step 831, upon receive the PDU session modification command,UE 801 evaluates the command and checks whether such command causes anyconflict of the default QoS rule policy. When UE determines the commandcarries a QoS rule operation to effectively delete the existing defaultQoS rule, UE knows that the command causes conflict for the one and onlyone DRQ policy. In step 841, UE 801 send a PDU session release requestto the network. In step 851, UE 801 receives a PDU session releasecommand from the network. In step 861, UE 801 sends a PDU sessionrelease complete to the network. In another embodiment of step 841, UE801 send a PDU session modification command reject back to the network,with a proper cause, e.g., semantic error in the QoS operation.

FIG. 9 is a flow chart of a method of QoS rule management for PDUsession establishment in accordance with one novel aspect. In step 901,a UE transmits a protocol data unit (PDU) session establishment requestin a mobile communication network. In step 902, the UE receives a PDUsession establishment accept from the network. The PDU sessionestablishment accept indicates to the UE to establish the PDU sessionand to create one or more QoS flows with one or more QoS rules. In step903, the UE releases the PDU session when the UE determines that morethan one QoS rules are set by the network to be a default QoS rule forthe PDU session.

FIG. 10 is a flow chart of a method of QoS rule management for PDUsession modification in accordance with one novel aspect. In step 1001,a UE establishes a protocol data unit (PDU) session in a mobilecommunication network. The PDU session is associated with a defaultQuality of Service (QoS) rule. In step 1002, the UE receives a PDUsession modification command from the network. The PDU sessionmodification command comprises commands for modifying the default QoSrule of the PDU session. In step 1003, the UE determines whether the PDUsession modification command causes a conflict for a default QoS rulepolicy. In step 1004, the UE rejects the PDU session modificationcommand or releasing the PDU session upon determining the conflict forthe default QoS rule policy. In one example, the PDU sessionmodification command is for the UE to add another QoS rule as thedefault QoS rule. The UE rejects the PDU session modification command bysending a PDU session modification command reject message with an errorcode. In another example, the PDU session modification command is forthe UE to delete the default QoS rule, to delete all packet filterswithin the default QoS rule, or to change the DQR setting. The UErelease the PDU session by sending a PDU session release request.

Although the present invention has been described in connection withcertain specific embodiments for instructional purposes, the presentinvention is not limited thereto. Accordingly, various modifications,adaptations, and combinations of various features of the describedembodiments can be practiced without departing from the scope of theinvention as set forth in the claims.

What is claimed is:
 1. A method, comprising: establishing a protocoldata unit (PDU) session by a user equipment (UE) in a mobilecommunication network, wherein the PDU session is associated with adefault Quality of Service (QoS) rule; receiving a PDU sessionmodification command from the mobile communication network, wherein thePDU session modification command comprises commands for performing a QoSrule operation related to the default QoS rule of the PDU session;determining whether the PDU session modification command causes aconflict for a default QoS rule policy, wherein the conflict isdetermined when a default QoS rule for the PDU session is to be deleted,and wherein the QoS rule operation involves deleting the default QoSrule, deleting all packet filters within the default QoS rule, orchanging a Default QoS Rule (DQR) setting; and releasing the PDU sessionupon determining the conflict for the default QoS rule policy.
 2. Themethod of claim 1, further comprising: transmitting a PDU sessionmodification request to the mobile communication network and in responsereceiving the PDU session modification command.
 3. The method of claim2, wherein the PDU session modification request comprises UE proposalsrelated to create, modify, or delete QoS rules.
 4. The method of claim1, wherein the default QoS rule policy mandates one and only one defaultQoS rule for the established PDU session.
 5. The method of claim 1,wherein the UE releases the PDU session by sending a PDU session releaserequest.
 6. A User Equipment (UE), comprising: a protocol data unit(PDU) session handler that establishes a PDU session in a mobilecommunication network, wherein the PDU session is associated with adefault Quality of Service (QoS) rule; a receiver that receives a PDUsession modification command from the mobile communication network,wherein the PDU session modification command comprises commands forperforming a QoS rule operation related to the default QoS rule of thePDU session; and a config and control circuit that determines whetherthe PDU session modification command causes a conflict for a default QoSrule policy, wherein the conflict is determined when a default QoS rulefor the PDU session is to be deleted, and wherein the UE releases thePDU session upon determining the conflict for the default QoS rulepolicy, and wherein the QoS rule operation involves deleting the defaultQoS rule, deleting all packet filters within the default QoS rule, orchanging a Default QoS Rule (DQR) setting.
 7. The UE of claim 6, furthercomprising: a transmitter that transmits a PDU session modificationrequest to the mobile communication network and in response receivingthe PDU session modification command.
 8. The UE of claim 7, wherein thePDU session modification request comprises UE proposals related tocreate, modify, or delete QoS rules.
 9. The UE of claim 6, wherein thedefault QoS rule policy mandates one and only one default QoS rule forthe established PDU session.
 10. The UE of claim 6, wherein the UEreleases the PDU session by sending a PDU session release request.